Valve spring cap-lock assembly and method and tool for assembly onto a valve stem

ABSTRACT

This invention provides a tool and method for assembling a valve spring retainer cap and lock onto the end of a valve stem with the valve spring in place and a retainer cap and lock assembly held together by a deformable plastic tube.

United States Patent [191 Seiler et a1.

[451 Feb. 26, 1974 VALVE SPRING CAP-LOCK ASSEMBLY AND METHOD AND TOOL FOR ASSEMBLY ONTO A VALVE STEM Inventors: Donald J. Seiler, Mentor; John H.

Shalaty, Wickliffe; Frederick V. Anderson, Willoughby, all of Ohio Assignee: TRW Inc., Cleveland, Ohio Filed: June 30, 1971 Appl. No.1 158,255

US. Cl 123/90.67, 123/90.28, 29/213, 29/214, 29/215, 29/249, 29/156.7 R

Int. Cl. F021 3/10, 823p 13/00 Field of Search 123/9067, 90.28; 29/213, 214, 29/215, 249, 156.7 R

References Cited UNITED STATES PATENTS 5/1967 Clark 29/249 Primary Examiner-Laurence M. Goodridge Assistant Examiner-Ronald B. Cox

Attorney, Agent, or Firm-Hill, Sherman, Meroni, Gross & Simpson 5 7 ABSTRACT This invention provides a tool and method for assembling a valve spring retainer cap and lock onto the end of a valve stem with the Valve spring in place and a retainer cap and lock assembly held together by a deformable plastic tube.

26 Claims, 17 Drawing Figures PATENTED ZE 74 SHEET 0F 6 Fig, ff

Z WTTORNEYS VALVE SPRING CAP-LOCK ASSEMBLY AND METHOD AND TOOL FOR ASSEMBLY ONTO VALVE STEM BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to valve spring cap-lock assemblies and to a pre-assembled cap and lock assembly and a tool and method for attaching valve spring caps and locks to a valve stem.

2. Prior Art Many methods of attaching a valve spring cap to the valve stem of an internal combustion engine valve have been proposed. However, one of the most popular methods is to provide an external groove around the valve stem adjacent the free end or tip of the valve and to then provide a tapered central opening in the spring cap. A collet lock assembly having a tapered outer diameter with a cylindrical inner diameter having a circumferential inner diameter rib is then placed in the tapered opening of the cap. The rib is indexed with the valve groove so as to project thereinto. The action of the spring tends to force the cap away from the valve tip so that the rib contacts the upper edge of the groove. Thus, the tapered opening of the valve is continually urged against the tapered outer diameter of the locks which are held in place on the valve tip. By providing a mating taper between the cap and the locks, the cap is retained on the end of the valve.

In order to allow the end of the valve tip which has a diameter greater than the diameter of the groove to be pushed through the valve lock for assembly, the valve lock must of necessity be able to increase in diameter. Although one-piece valve locks capable of increasingin diameter have been suggested, many assemblies use multiple-piece collet locks. Most popular is a pair of approximately 180 circular locks which mate together to form the complete lock around the valve stem.

Whether using the two-piece collet lock or a onepiece collet lock or other previously suggested types, extreme difficulty is encountered in assembling the locks to the end of the valve stem during assembly of the engine. It is possible for one of the locks or a portion thereof to become misaligned and to not securely mate with the valve tip groove. This provides for an inadequate lock of the valve cap to the valve stem. Further,'the locks are generally small and for that reason difficult to handle during assembly. Further, for various reasons, including ease of shipment and handling, it is desirable to preassemble the valve cap and the locks prior to the time they are assembled on the engine. Additionally, oftentimes it is desirable to provide a valve stem oil shield. Many of such oil shields are preassembled onto the cap while others are free from the cap but inasmuch as they are generally assembled onto the valve stem at the same time the cap is, it has been thought desirable to attach them to the valve cap in a temporary manner so as to allow assembly of both the oil shield and the cap to the valve tip at the same time. The prior art has not provided an adequate solution to the problem of providing a pre-assembled cap and shield and/or a pre-ass'embled cap and lock assembly. It has been suggested to elongate the lock to provide for outturned flanges at the bottom which would extend outwardly of the cap to maintain the lock in the cap. In order to provide such flanges while still allowing the locks to move within the cap a sufficient axial distance to allow insertion of the valve stem, the locks have of necessity been axially longer than desirable and cumbersome.

in addition, the prior art has not provided an adequate solution to the problems of assembling the cap and locks onto the end of the valve stem. Whether the cap-lock is pre-assembled or not, difficulties are encountered in attachment to the valve tip. Especially in the case of two-piece locks, it is possible for one of the locks to become misaligned or to even fall out of the assembly during installation. Further, in order for the locks to work properly, they must function as a cooperating pair and if one of the locks gets inserted further into the central cavity or well of the cap than the other, it is impossible for both locks to index properly with the groove of the valve tip. Although the art has suggested many ways of installing the locks, none of the suggestions have adequately solved the problems of installation.

SUMMARY The present invention overcomes the disadvantages of the prior art in connection with collet locks and provides a tool for the installation of collet locks onto the end of a valve stem interior of the central well of a valve spring retainer cap. Further, the invention provides a modification of the tool for use with multi-bead locks and multi groove valve stems. In addition, the invention provides for a pre-assembled cap-lock combination where the collet lock is pre-assembled into the valve spring retainer cap and retained therein by a plastic cylinder having an out-turned flange at one end which overlies the wide end of the collet locks and a deformed outturned flange adjacent the other end which overlies a portion of the narrow open end of the well of the cap, thus maintaining the locks in the cap. In a modified form of the invention, the plastic cylinder is also used to position an oil shield and to pre-assemble it to a cap-lock-shield assembly.

The installation tools subject to this invention also provide means for removing the plastic retainer of the pre-assembly during assembly of the valve cap and locks onto the valve stem.

It is therefore an object of this invention to provide method, apparatus and tools for the assembly of valve spring retainer caps and collet locks onto the end of an internal combustion engine valve stem.

It is a further object of this invention to provide a preassembled valve spring retainer cap and collet lock assembly wherein the collet lock is retained in the well of the valve spring cap by a disposable member.

It is a more specific object of this invention to provide a pre-assembled valve spring retainer cap and collet lock assembly wherein the collet lock is retained in the central well of the retainer cap by a plastic cylinder having out-turned flanges at either end, one of which overlies portions of the wide end of the collet lock and the other of which overlies portions of the retainer cap, the disposable part being adapted to retain an oil shield in position adjacent the valve spring retainer cap prior to assembly.

It is yet another object of this invention to provide a method of assembling collet locks on valve stems. It is yet another and more specific object of this invention to provide a tool for assembling valve spring retainer caps and collet locks on the end of a valve stem.

BRIEF DESCRIPTION OF THE DRAWINGS Other objects, features and advantages of the invention will be readily apparent from the following de' scription of certain preferred embodiments thereof, taken in conjunction with the accompanying drawings, although variations and modifications may be effected without departing from the spirit and scope of the novel concepts of the disclosure, and in which:

FIG. 1 is a cross-sectional view of a pre-assembled cap-lock according to this invention.

FIG. 2 is a cross-sectional view similar to FIG. 1, illustrating a cap-lock pre-assembly with an attached oil shield.

FIG. 3 is a view similar to FIGS. 1 and 2 illustrating a cap-lock pre-assembly with an oil shield maintained in place adjacent the assembly.

FIG. 4 is a cross-sectional view similar to FIG. 1 illustrating the assembly of this invention prior to deformation of the retaining tube.

FIG. 5 is a fragmentary cross-sectional view of the deformation of the tube.

FIG. 6 is a fragmentary, cross-sectional view of a tool for assembling the valve spring cap and lock preassembly onto a valve stem illustrating the cap and lock pre-assembly and the valve stem and valve spring.

FIG. 7 is a view similar to FIG. 6 illustrating the tool in a first operating position.

FIG. 8 is a view similar to FIGS. 6 and 7 illustrating the tool in another operating position.

FIG. 9 is a view similar to FIGS. 6 through 8 illustrating the tool in a further operating position.

FIG. 10 is a view similar to FIGS. 6 through 9 illustrating the tool in a further operating position.

FIG. 11 is a fragmentary cross-sectional view of the valve spring retainer cap and lock as assembled on the valve stemby the tool.

FIG. 12 is a diagrammatic view illustrating the use of the tool of FIGS. 6 through 10 in an assembly line.

FIG. 13 is a fragmentary cross-sectional view of a modified multiple bead collet lock and valve spring retainer cap received on a multiple groove valve stem.

FIG. 14 is a view partially in section of a modified tool for the assembly of multiple bead collet locks and valve spring retainer caps onto a multiple groove valve tip.

FIG. 15 is a partially cross-sectional view of a portion of the tool of FIG. 14 taken along the lines XVXV of FIG. 14.

7 FIG. 16 is a view similar to FIG. 14 illustrating an operating position of the tool of FIG. 14.

FIG. 17 is a view similar to FIG. 16 illustrating a further operating position of the tool.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 illustrates a pre-assembled valve spring retainer cap-lock assembly 10. The assembly includes a valve spring retainer cap 11 and a pair of semi-circular collet locks 12 and 13. The valve spring retainer cap 11 has a central well 14 having a circular tapered side wall 15. In some instances, the valve spring retainer cap may have a rotatable bearing member 16 received in the well, the bearing member 16 having a circular tapered wall central opening 17. In any event, whether the retainer cap 11 illustrated in FIG. 1 includes the rotating bearing member 16 or whether the retainer cap such as the cap 11b of FIG. 2 has simply a circular central tapered well 14b, the tapered wall of either the bearing member or the cap mates with a frustoconically tapered outer diameter wall 18 on the collet locks 12 and 13. Thus, the collet locks l2'and 13 are wedge-shaped with a substantially cylindrical inner diameter and a tapered outer diameter. The collet locks when in place in the cap increase in thickness from their bottoms 20 to their tops 21 as the central well increases in crosssection from the bottom 22 of the retainer cap to the top 23 thereof.

The taper of the 'collet locks outer diameter and the taper of the valve spring retainer caps central well match so that although the collet locks are freely receivable through the wide end of the well, they can project thereinto only to a point where they will mate with the taper of the well, preventing further axial movement of the locks. Normally, the collet locks 12 and 13 comprise two half-circular members which cooperate to form a complete lock.

The inner diameter of the collet lock contains a radially inwardly projecting circumferential bead or rib 25 which is adapted to be received into a groove around a valve stem. Inasmuch as the valve stem has a dimension to either side of the groove which is greater than the inner diameter dimension of the bead 25, the collet lock must be capable of increasing in diameter to accommodate the non-grooved portion of the valve stem until the bead is aligned with the grooves. For this reason, a pair of half-circular collet locks may be used or a single collet lock having a split may be used. In the embodiments illustrated, it is to be understood that a pair of collet locks are illustrated. However, it is to be understood that whenever the terms collet lock or valve spring retainer lock are used in the description or claims, it is intended to refer to either a one-piece or a multi-piece lock assembly.

When received in the tapered well of the valve spring retainer cap, the collet locks could move only in one axial direction inasmuch'as movement in the other axial direction is prevented by the wedge nature of the outer diameter collet lock mating with the tapered inner diameter of the valve spring retainer well. This invention provides a method of preventing movement in the other axial direction in order to provide a preassembled valve spring retainer cap-lock assembly.

This retention is accomplished by a plastic tube 26' which has an outturned lip 27 at one end thereof to overlie the wide end of the collet locks at the top 21 thereof, and which is deformed at the other end 28 to provide an outturned lip 29 overlying the bottom 22 of the valve spring retainer cap. Thus, movement of the tube 26 in an axially upward direction is prevented by contact between the outturned lip 29 and the bottom 21 of the retainer cap while axially upward movement of the collet locks 12 and 13 is prevented by contact between their top surfaces 21 and the undersurface 30 of the lip 27 at the opposite end of the tube 26.

Thus, there is presented a pre-assembled cap-lock assembly which includes at its simplest a collet lock, a valve spring retainer cap, and a restraining tube having outturned lips at both ends.

Alternatively, the assembly may include a rotator member such as the member 16 illustrated in FIG. 1 which is also retained in the valve spring retainer cap 11 due to the co-action between the collet locks restraining movement of the rotator member in one direction, the cap restraining movement of the rotator member in the other direction, and the tube restraining movement of the collet locks. Further, as illustrated in FIG. 3, the tube may be elongated as at 35 so that its bottom end 36 is spaced axially beyond the bottom end 37 of the retainer cap and a valve stem oil shield 38 is received around the extension of the tube, the end 36 of the tube being flared beyond the portion of the oil shield received around the tube whereby the oil shield portion is enclamped between the bottom 37 of the valve spring retainer cap and the flared portion of the tube to maintain the oil shield in position adjacent the retainer cap. Axial movement of the tube is again restrained as in prior embodiments due to the outtumed lip 27 at the top end thereof being in contact with the collet locks 12 and 13 and the flared end 36 being in contact with an undersurface 39 of the oil shield.

A further embodiment is illustrated in FIG. 2 where the oil shield 40 is attached to the valve spring retainer cap 1 lb independently of the retainer tube and the tube 26 is utilized solely to maintain the collet locks 12 and 13 within the valve spring retainer cap 11b with the flared end 3612 of the tube overlying a portion of the bottom 22b of the valve spring retainer cap intermediate the bottom and a wiping lip portion 42 of the oil shield.

As best illustrated in FIG. 4, the tube 26 initially consists of a cylindrical tubular portion 45 having an outturned flange 46 at one end, thereof. In the preferred embodiment, a portion 47 of the tube adjacent the end remote from the outtumed lip end may have a larger internal diameter than the remaining portion. The end 48 of the tube 26 remote from the outtumed lip 46 is flared outwardly after insertion of the tube into the central opening of-the collet locks 12 and 13 after they have been placed in the central well of the valve spring retainer cap or rotating member if such is used.

The end 48 may be flared by any desirable operation, however in a preferred embodiment, the tube is made of a thermosetting plastic which is permanently deformable under influence of heat. In this manner, as illustrated in FIG. 5, after the tube has been placed into the collet lock and retainer cap assembly,a thermal forming tool 50 having an end. configuration 51 adapted to flare the end 48 of the tube is pushed into the end 48. A retaining member 52 may be inserted into the other end of the tube to maintain it in place in the collet lock-valve spring retainer cap assembly. While the tool 50 may be of any desired type such as hot pin," spinning, etc., it has been found very acceptable to use an ultrasonic tool. It is of course to be understood that the invention could be practiced with a cold-formable plastic and tool as well as a thermally formable plastic and tool.

It will therefore be understood that this invention provides a preassembled valve spring retainer capcollet lock assembly wherein the collet lock is retained in the valve spring retainer cap central well by a tubular member which has an outtumed lip adjacent one end which overlies an end of the collet lock remote from the bottom of the well and an outtumed lip at the other end of the tube which overlies the bottom of the valve spring retainer cap, thereby retaining the collet locks in the well. .A modified form of the invention utilizes an elongated tube which projects through the valve spring retainer cap and through a portion of an oil shield and is thereafter flared to entrap the portion of the oil shield between the bottom of the valve spring retainer cap and the flared end of the tube. Although the figures illustrate a two-piece single bead collet lock, it is to be understood that the invention can be practiced with other collet locks such as for example a single-piece single-bead collet lock or a single or multiple piece multiple-bead collet lock as is hereinafter illustrated.

This invention also provides a tool and method of assembling a valve spring retainer cap-lock assembly onto the stern of a valve.

A first preferred embodiment of the tool is illustrated in FIGS. 6 through 10. The tool, as illustrated in those figures, is primarily designed for use with single bead collet locks. Although the drawings illustrate, and the discussion which follows describes, the use of the tool in connection wiht the pre-assembled cap-lock described above, it is to be understood that the tool can be used to assemble a cap-lock group onto a valve stem without the practice of the above-described invention. Thus, with suitable pre-assembly steps or cap and lock feeding devices, the tool can be utilized without reference to the above-described tube 26.

As best illustrated in FIG. 6, the tool 60 of this invention comprises a first body portion 61 having a variously configured open interior 62 and an end surface 63 with a variously configured opening 64 in the end surface 63 communicating to the interior hollow area 62. The end 65 of the tool opposite the end 63 may be closed by a cap 66 having an opening 67 therein communicating to the hollow interior 62. The outside surface 68 of the cap 66 provides a tool end surface opposite the surface 63.

The cap 66 may be attached to the body portion 61 by any desirable means such as removable screws 69.

The opening 64 in the end 63 forms a central recess 70 in the end wall 63 which recess extends into the body 61 to a ledge 71, the ledge having a central opening 72 therein having a diameter smaller'than the opening 64. The opening 72 communicates with an interior cavity 73 having diverging walls in a direction herein described as axial away from the end 63. The cavity 73 is preferably circular and the walls preferably diverge at an angle of approximately 15 as hereinafter described. The diverging wall 74 of the cavity 73 extends axially into the body 61 and terminates in an interior radially inwardly directed ledge 75 which extends inwardly a short distance terminating in a peripheral wall 76 defining a central cavity 77 which extends axially into the housing 61 to a larger diameter cavity 78. The larger diameter cavity 78 extends axially back into the body portion 61 for substantially the entire distance to the cap 66. Thus, the open interior 62 of the body 61 comprises from the end 63 to the cap 66 in sequence the opening 64, the recess 70, the diverging walled cavity 73, the central cavity 77 and the larger diameter cavity 78.

A piston 80 is received in the larger diameter cavity 78. The piston 80 has an end wall 81 towards the end 63 of the body. The end wall 81 is adapted to abut against the ledge 82 formed at the intersection of the central cavity 77 and the larger diameter cavity 78. The piston 80 has a diameter sufficient to substantially fill the cavity 78 and an axial length shorter than the cavity 78 whereby when the end wall 81 is abutted against the ledge 82, the opposite end wall 83 of the piston is spaced from the inner surface 84 of the of the cap 66. The piston 80 is movable in the cavity 78.

The piston 80 has a central opening 85 therein which is stepped to provide a smaller diameter opening 85a adjacent the end 81 and a larger diameter opening 85b adjacent the end 83. An internal ledge is formed at the intersection of the small diameter opening 85a and the large diameter opening 85b.

A compression spring 88 having an inner diameter equal to or greater than the diameter of the small diameter portion 85a of the piston is entrapped between the ledge 86 and the cap 66. The inner face 84 of the cap 66 may have a recess 89 therein for receiving the end 90'of the spring 88. Thus, the spring 88 acts to urge the piston against the ledge 82, the piston being movable in the cavity 78 by compression and expansion of the spring 88.

A plunger 92 is received in the housing 61 interiorly of the piston 80 and is acted upon by the piston. The plunger 92 is cylindrical, preferably having a hollow interior 93 defined by a'cylindrical wall 94 having an axial front end 95 and a rear end 95b. The diameter of the plunger 92 is larger adjacent the front end 95 forming an outer diameter ledge 96 for abutment by the end 81 of the piston when the plunger is received through the opening 85 in the piston. The remainder of the plunger 92 preferably has a diameter substantially equal to the smaller diameter portion 85a of the opening 85 whereby the plunger is press-fit in the piston to maintain it therewith and prevent the plunger from dropping out of the tool. Thus, the plunger is normally maintained in contact with the ledge 96 of the outer diameter of the plunger and the front end 81 of the piston. Thus, the piston, by action of the compression spring 88, is effective to force the front end 95 of the plunger towards the end 63 of the housing. It is to be understood that although the piston and plunger are herein described as separate members, that in some embodiments they may be constructed in a single piece with the compression spring 88 acting against a portion of the plunger.

The tool 60 is completed by an abutment plate 97 received in the recess 70 and bottomed against the ledge 71. The abutment plate 97 is preferably of a wearresistant material such as a metal alloy and is fastened in the recess 64. The plate 97 has a central opening 98 therein aligned with the opening 72 of the cavity 73. The opening 98 converges from the underside 99 of the plate 97 wherein the opening 98 is as large as the cavity 73 at the ledge 71 to the outer side surface 100 wherein the opening 98 is dimensioned with respect to the central well of the cap-lock pre-assembly being worked upon. Thus, the opening 98 at the outer side 100 will be as large as the large diameter end of the central well of the individual cap-lock assembly. In this manner, it can be seen that the opening 98 in the wear plate 97 has an inner diameter surface which acts as a slope face connecting the wall of the central well of the cap lock to the diverging wall 74 of the cavity 73 when the caplock is received in the recess 64 as illustrated in FIG.

The end 95 of the plunger 92 may have a tapered exterior surface as at 101 and has an inturned flange 102 defining a central opening 103 to the hollow interior 93 of the plunger 92. The wall 104 of the inner diameter flange 102 is preferably tapered and the radially inner wall 105 of the flange 102 provides an internal ledge at the axial end of the plunger.

The tool 60 is used to assemble a valve spring cap and collet lock onto the end of a valve stem with the valve spring entrapped between the cap and the engine head.

The operation of the tube will be described for illustrative purposes in connection with FIGS. 6 through 10 as being used with the cap-lock pre-assembly of FIG. 1. However, it is to be understood that the tool may be used with any of the illustrated pre-assemblies or with any other preassemblies of this type and it is to be further understood that the tool can be used independent of a pre-assembly. That is to say that the tool may be used in any instance where the collet locks have been fed into the central well of the valve spring cap prior to the application of the tool.

As illustrated in FIG. 6, functioning of the tool begins when the cap-lock assembly 10 is placed on the top of the valve spring above the valve stem 111 with the tip end 112 of the valve stem axially aligned with the flared end 48 of the tube 26 of the pre-assembly. The tool is then positioned above the pre-assembly, spring, and valve tip group and lowered until the pre-assembly is received in the recess 70 with the top 23 of the retainer cap bottomed against the underside wall 100 of the abutment plate 97. At this point, the tapered central well opening 17 of the bearing member 16 of the preassembly is aligned with the tapered opening 98 of the plate 97 as has been previously described..The tool may be associated with a moving ram 114 for movement thereof, the ram being fragmentarily illustrated in FIG. 6 and including a central opening 115 for receipt of the end 94 of the plunger 92. It will be understood that although for purposes of this description the tool is described as being aligned over the cap-lock, spring, and valve tip group, vertical positioning may be changed so that the tool is aligned in a position other than vertical and above the group and indeed the tool may move upwardly into contact with a group positioned above it.

After attaining the initial position of FIG. 6, the tool 60 is further moved against the group of components to the position of FIG. 7 where the valve spring 110 has been compressed sufficiently to force the pre-assembly l0 downwardly until the end 112 of the valve stem 111 has been received interiorly of the flared opening 48 of the tube 26. During this step, the flared opening acts as an alignment member guiding the movementof the valve tip which normally has a tapered end 116. It will be appreciated that during the assembly, the valve stem 1 11 is maintained in a set position so that further movement of the tool 60 from a position illustrated in FIG. 7 will cause a relative movement between the preassembly 10 and the valve tip, inasmuch as the compression spring 110 will always maintain the preassembly 10 against the ledge at the bottom of the recess 70 formed by the underside 100 of the plate 97 which in turn is bottomed against the ledge 71 and afflxed thereto.

As the tool 60 continues to descend with respect to the valve tip 112 to the position illustrated in FIG. 8, the tube 26 will be forced out of the central well 17 of the pre-assembly, the flared end 48 of the tube being deformed to be pushed through the opening in the bottom 22 of the retainer cap which communicates with the central well. Inasmuch as the retainer cap in all instances, and the rotating member 16 in those assemblies which have a rotating member are bottomed against the plate 97, they will not be axially moved. However, inasmuch as the opening 98 in the plate 97 and the cavity 73 of the tool 60 are larger than the outturned lip 27 of the tube 26 and the maximum assembled diameter of the collet locks 12 and 13, they will be forced into the interior of the tool 60 by the abutment with the stationary valve tip 112.

By constructing the opening 103 formed by the inner diameter 104 of the ledge 102 of the plunger 92 with a diameter larger than the diameter of the flange 27 of the tube 26 but smaller than the outer diameter of the top of the collet locks 12 and 13, the collet locks and tube 26 will be forced upwardly by contact with the valve tip 112 to the position illustrated in FIG. 8 where the collet locks 12 and 13 are bottomed against the axial end of the plunger 92 with the flanged end 27 of the tube 26 pushed into the hollow interior 93 of the plunger 92 through the opening 103.

Further movement of the tool 60 from the position illustrated in FIG. 8 will cause relative movement of the plunger 92 inasmuch as the tops of the collet locks 12 and 13 are in contact with the plunger 92 at the end thereof 95. As long as the collet locks 12 and 13 have an internal diameter at any point less than the diameter of the top of the valve tip 112, they will be forced to move with the valve tip into the descending tool 60. This will force them against the bottom of the plunger which force will act against the compression spring 88 to compress it within the cavity 62 of the housing 61, thereby allowing movement of the plunger 92 with respect to the housing. 1, y

As the tool 60 continues to descend, the collet locks will be pushed outwardly from the central well 17 a sufficient distance to allow the locks to move apart from one another to increase their interior diameters so as to receive the valve tip 112. At this point, the collet locks will normally have a major portion received within the cavity 73 of the housing. The tapered walls of the cavity will allow the collet locks to open away from one another a distance at the top of the locks at least equal to the expansion distance at the bottom. Thus, the diverging angle of the wall 74 is at least equal to the wedge angle of the locks, which is normally the angle of the central well.

During all of this movement, pressure will continue against the top of the collet locks from the plunger 92. However, as the valve tip moves through the collet locks, it will continue to push the tube 26 into the hollow interior 93 of the plunger until the point illustrated in FIG. 9 is reached where the collet locks 12 and 13 have their major portion positioned within the cavity 73 and the valve tip 112 has moved between the collet locks a sufficient distance to have forced the entirety of the tube 26 into the hollow interior 93 of the plunger 92. At this point, the flared end 48 of the tube will again expand into contact with the wall of the plunger. Inasmuch as the flare will be greater than the diameter of the inturned lip opening 103 of the plunger, the flared end 48 will bottom against the ledge 105 and thereby be retained within the hollow interior 93 of the plunger independently of the presence of the valve tip 112.

At this point in time, the force acting against the axial end of the plunger will cease inasmuch as the collet locks are now received around the outer diameter of the valve tip 112 and the valve tip 112 has moved sufficiently to allow freedom of movement of the collet locks back towards the central well of the retainer cap. At this point, the compression spring 88 will act against the piston which in turn acts against the plunger to force the collet locks into the central well 17 around the valve tip 112.

The plunger will act to force the collet locks into the central well until a major portion of them is received in the well with the rib 25 of the locks in contact with the outer diameter of the valve tip 112 at a spot level with or below the rib receiving groove 120 of the valve tip. Inasmuch as the inner diameter of the rib 25 is less than the outer diameter of the non-grooved area of the valve tip 112, the collet locks cannot be forced entirely into the central well to a position where they are at their operating diameter. Therefore, they will be pushed or dropped into the well only as far as contact between the inner diameter of the bead 25 and the outer diameter of the valve stem. This position is illustrated in FIG. 10 where it is shown that the piston has again moved to contact with the ledge 82 and the collet locks have been moved back into the central well 17 of the retainer cap with the beads 25 below the grooved area 120 of the valve. It is to be understood that contact between the end of the plunger and the top of the collet locks is not illustrated at this point because of the vertical positioning of the tool above the group. However, in those instances where the tool is used at a different position from the group, such as by way of example below it, the tops of the collet locks would still be in contact with the axial end 95 of the plunger.

Movement of the plunger with respect to the retainer cap is such that when the piston 80 is bottomed against the ledge 82, the collet locks will be positioned with respect to the valved tip, when the tool 60 is at the end of its stroke, such that the beads 25 are axially below the groove 120. It will be further understood that the slope of the diverging wall 74 of the cavity 73 is approximately the same as the slope of the central well 17 and the tapered wall 98 of the opening in the plate 97 will communicate the wall 74 of the cavity 73 to the wall of the central well 17 so as to prevent bind-up of the collet locks within the tool whereby the plunger will be effec tive to force the collet locks back into the central well after passage of the valve tip therebetween. After the tool has reached the end of its stroke as is illustrated in FIG. 10, it is withdrawn. During the withdrawal, the valve tip will move relative to the collet locks until the bead 25 snaps into the groove 120. Further withdrawal of the tool 60 will result in the movement of the collet locks with the valve tip into the central well 17 until the locking position is reached as is illustrated in FIG. 11. The tool 60 may then be removed, resulting in a finally assembled valve spring retainer lock and stem assembly with the beads 25 of the collet locks locked securely in the groove 120 of the valve tip 112 and the locks received in the central well 17 of the valve spring retainer cap 11.

FIG. 12 schematically illustrates the use of a tool 60 such as has been described in a production line situation. An engine head 120 having a plurality of valve guide openings 121 therein is moved on a surface 122 positioned below the ram 114 mounted tool. The first step in the assembly is the mounting of the valves 122 in the head 120 with the valve tips 112 projecting above the head 120. Next, the valve springs are positioned atop the head around the valve stems.

Next, the cap-lock pre-assembly is positioned atop the springs 110. In the next step, the tool 60 is brought into contact with the cap-lock pre-assembly in the position illustrated in FIG. 6. The tool 60 then descends with respect to the head 120 moving through the positions illustrated in FIGS. 7 through 10. The tool is then removed and the final assembly is completed with the cap-lock combination 10a assembled onto the valve tip 112.

It will be appreciated that the tube 26 will be retained within the hollow interior of the plunger 92 by contact between the flared end of the tube and the ledge 105 of the axial end 95 of the plunger. The tube may be removed from the interior by any desired method such as for example by a suction connection between the axial end 94 of the tube and an outside source.

It will be further understood that if desired, the plunger 92 and piston 80 may be constructed as a single member with the compression spring 88 operating against a portion of the single member.

9 FIGS. 13 through 17 illustrate a modification of the tool 60 for use withmulti-bead collet lock assemblies.

In such multi-bead assemblies, the collet locks 112 and 113 have a multiplicity of beads 127 on their inner diameter which beads coact with a multiplicity of grooves 128 on the tip 129 ofa valve stem 130 in much the same manner as has been heretofore described for single bead locks.

FIG. 13 illustrates such a multiple bead cap-lock assembly in position on a valve stem. The assembly comprises the multiple bead locks 112, 113, a valve spring retainer cap 131 having a central well 132, a valve stem 130 having a tip end 129 with multiple grooves 128 therein for meshing with the beads 127, an oil shield 133 received around the valve stem 130 and a valve spring 134. I

In assembling the multiple bead lock on to a multiple groove valve tip, all of the heretofore mentioned problems exist. In addition, it is important that the bottom head of the lock mesh with the bottom groove of the tip. It is possible for the bottom bead to mesh with a groove other than the bottom groove, thereby resulting in an improper assembly.

FIG. 14 illustrates an assembly tool 160 for assembling multiple bead locks onto a multiple groove valve stem correctly. The tool 160 includes a body portion 161 having a hollow interior 162. The body 161 has a first axial end 163 with a recess 164 therein. The recess 164 has a centrally disposed opening 172 therein which communicates the recess with a cavity 173 having diverging walls 172 in substantially the same manner as I the recess 70 of the tool 60 was communicated to the cavity 73. It will be understood that in the embodiment illustrated in FIGS. 14 through 17, the equivalent of the abutment plate 97 is not used, however such a plate may be used if desired. The cavity 173 communicates through a reduced diameter opening 176 to a larger diameter cavity 178. A piston 180 operates in the cavity 178 in much the same manner as the piston 80 operated in the cavity 78 of the tool 60. A compression spring 188 is positioned between a portion of the cavity and a closure cap 166 forming the axial end opposite the end 163 of the housing body 161. A plunger 192 is received through the body 161 and is acted upon by the piston 1,80.

The tool 160 includes a pilot pin assembly 200 received in the hollow interior 193 of the plunger 192.

The pilot pin 200 is acted upon by a secondary spring 201 received in the hollow interior 193 between a piston 202 formed on the pilot pin and a plunger closure member 203. A detent assembly 204 cooperates with a groove 205 around the pilot pin to lock the pilot pin in a set position relative to the plunger which has its axial end 194 fastened to the detent assembly by means such as a set screw 207.

The pilot pin and detent assembly operate together to limit the movement of the plunger with respect to the valve tip as will hereinafter be explained.

As best illustrated in FIG. 15, the detent assembly includes a movable lock member 210 having a claw lock 211 which includes a central slot 212 dividing two tongue locks 213 which are dimensioned to intersect with the groove 205 in the pilot pin stern 214 insuch a manner as to limit movement of the stem 214 with respect to the detent lock. The detent lock being coupled to the plunger in fixed position and movable therewith.

The claw lock 211 is spring-urged into locking position by a spring 216 received within the body 217 of the detent and is withdrawable from the lock position by actuation of a knob 219. Although a manual detent is illustrated, it is to be understood that an automatic or machine-operated detent can be utilized.

The pilot pin assembly consists of the stem 214 which extends entirely through the tube having an axial end 220 projecting beyond the detent assembly and a tip abutting axial end 221 projecting normally beyond the end 163 of the tool 160. The spring 201 acts against the piston 202 to urge the tip abutting end 221 out of the housing 161 until abutment between an adjustable screw 223 and a surface 224 of the detent.

Operation of the tool is initiated by alignment of the pre-assembled cap-lock assembly in the recess 164 with the cap 131 abutted against the bottom ledge 171 of the recess and with the multiple bead locks 112 and 113 received in the central well 117 of the cap 131 and retained therein by a flared end tube 126. The valve tip abutting end 221 of the pilot pin 200 projects through the tube 126.

The tool and pre-assembly is aligned with the valve tip 129. Movement of the tool with respect to the valve tip then commences from the position illustrated in FIG. 14.

As the tool is moved with respect to the valve tip, the relative movement of the tip is through the valve stem seal thence through the valve spring retainer cap displacing the plunger 192 and compressing the spring 188. By the time the tool reaches this point, the collet locks 1 12 and 113 will have been urged against the bottom axial end of the plunger to cause the plunger to move. As movement of the tool continues, the plunger will be forced backwardly in the tool until the axial end 183 of the piston bottoms against the closure cap 166. From that point on, further movement of the collet locks is prevented and the locks will be positioned within the diverging wall cavity 173. Further movement of the tool will cause a downward movement of the pilot pin and tube 126 within the tool housing 161. This results in a stripping of the tube from within the collet locks. The outturned flare of the tube acts to force the collet locks apart. This provides clearance for the valve stem to move between the lock hands without interference. This position is illustrated in FIG. 16. It will be understood that although we have herein described the initial movement as having the plunger and pilot pin mounted together until the piston bottoms, that depending on clearances, the pilot pin may move first until contact between the lock and the plunger.

At this point, the valve tip 129 has moved through the seal 133 and spring retainer cap 131. Further, the collet locks 1 l2 and 1 13 have been moved into the cavity 173 and are in contact with the end 195 of the plunger 192. The plunger has moved the maximum permissible distance and the piston 180 is abutted against the closure cap 166. Further, the valve tip has-moved beyond that point so as to cause compression of the pilot pin spring 201 moving the pilot pin piston 202 interiorly of the plunger and stripping the preassembly tube 126 from the remainder of the pre-assembly and positioning it interior of the hollow plunger. The further movement of the pilot pin with respect to the plunger has extended the pilot pin stem 214 beyond the surface 224 of the detent assembly 210 and aligned the groove 205 of the pilot pin stem 214 with the claw lock 211 of the detent. At this point, it is to be noted that the beads of the collet locks 212-213 are aligned with the grooves 128 of the valve stem.

At this point, i.e., when the beads are aligned with the grooves, movement of the tool 160 in the first direction stops. The claw lock of the detent is actuated to lock the pilot pin stem in position with respect to the plunger so that all further movement of the plunger must be in cooperation with movement of the pilot pin. Inasmuch as the pilot pin is in contact with the valve tip, therefore, movement of the plunger is restricted to movement of the valve tip even though there is no contact other than through the pilot pin of the plunger to the valve tip. Inasmuch as the collet locks are in contact with the plunger, movement of the valve tippilot pin-plunger connection will cause movement of the collet locks in the same direction.

The movement of the tool 160 is then reversed, withdrawing it from the valve tip 129. As the tool moves with respect to the valve tip, the spring 188 urges the plunger-pilot pin connection within the tool 160 thereby forcing the collet locks to accompany the withdrawal of the valve tip 129 from the interior of the tool. This position is illustrated in FIG. 17, where it is shown that the collet locks 112, 113 have been moved from the position of FIG. 16 back into the central well 117 of the spring retainer cap 131. Due to the taper of the spring retainer cap, the collet locks are drawn together. Due to the alignment between the beads and the grooves and the maintenance of that alignment by 'movement of the plunger only in cooperation with movement of the valve, the collet locks will be forced into the proper position around the valve tip. From the position illustrated in FIG. 17, the tool is removed from the valve tip entirely resulting in a completed valve spring retainer caplock assembly as illustrated in P16. 13.

it will be understood that this tool allows the initial movement of the tool with respect to the valve tip and pre-assembled cap-lock to force the collet locks out of the spring retainer cap in contact with the plunger. Only after they have been forced out and into the internal cavity of the housing, is the valve tip free to move between them. This is accomplished by bottoming the piston of the plunger thereby preventing further movement of the plunger while allowing the pilot pin to move within the plunger. After the valve tip has moved sufficiently interior of the housing 161 to align the grooves with the beads on the collet lock. the movement of the plunger is coupled to movement of the valve tip via the pilot pin and detent assembly. Thereaf ter, withdrawal of the tool from the valve stem allows the valve tip and the collet locks to move in unison into the tapered central well of the valve spring retainer cap where the collet locks will be enclosed about the grooved valve tip.

It will therefore be understood that our invention provides a preassembled cap-lock assembly for valve springs and a tool for assembling the assembly onto a valve stem and spring group. It will further be understood that the tool of this invention can be used independently of the preassembled cap-lock assembly of this invention.

Although we have herein set forth our invention with respect to certain specific principles and details thereof, it will be understood that these may be varied without departing from the spirit and scope of the invention as set forth in the hereunto appended claims.

We claim as our invention:

1. The method of automatically assembling and locking a valve spring retainer assembly onto a grooved valve stem surrounded by a valve closing spring, the assembly including a tapered well collar with a segmented internally beaded valve lock received therein, the lock having a valve spring engaging a flange which comprises: placing the lock in the tapered well collar,

feeding the assembly with the small end of the collar forming the leading end onto the valve stem while depressing the valve spring with the flange, thrusting the end of the stem against the lock in the collar to shift the lock toward the large end of the collar, retarding the shifting of the lock while continuing the thrusting of the valve stem thereagainst to move the stem into the lock and spread the lock segments apart, arresting the spreading of the lock, moving the valve stem through the lock until the stem groove is aligned with or beyond the internal bead of the lock and reversing the feeding of the assembly to expand the depressed valve spring for moving the tapered collar into wedged engagement with the valve lock constricting the lock segments around the valve stem, thereby securing the assembly to the stem with the lock beads seated in the groove and the locks forming a wedge connection between the valve stem and the collar.

2. The method of claim 1 wherein the retainer assembly includes a tube extending through the lock segment and anchored on the retainer and the valve stem is thrust against the tube and ejects the tube from between the lock segments when the shifting of the lock is arrested.

3. The method of claim 2 wherein the tube has an enlarged mouth receiving the end of the valve stem and a head overlying the valve lock and the thrusting action of the valve stem contracts the large end of the tube to pass through the collar and valve lock.

4. A tool for automatically assembling and locking a valve spring retainer assembly onto a grooved valve stem which comprises: a housing adapted to thrust against a valve spring retainer assembly resting on a valve spring surrounding the grooved stem of a valve and having a tapered collar with an internally beaded valve lock therein; said housing having a increasing di mension tapered recess adapted to receive the valve lock and a spring loaded plunger projecting into said recess; said plunger receiving the valve lock thereagainst when the assembly is thrust against the valve stem and the valve lock shifts out of the tapered collar into the tapered recess of the housing; said plunger being hollow and adapted to receive the valve stem therein to arrest the shifting of the lock relative to the stem for aligning the stem groove with the internal bead of the lock, and said housing being retractable to allow the valve spring to move the collar into wedging engagement with the valve lock on the stem.

5. The tool of claim 4 wherein the housing has a well receiving the retainer assembly and a plate bottomed in said well overlying the collar and having a central opening with a beveled opening diverging to the small end of the tapered recess of the housing.

6. The tool of claim 4 wherein the hollow plunger has an end wall for contacting said valve lock and said end wall has inturned lips.

7. A tool for automatically assembling valve spring retainer caps onto valve stems surrounded by valve closing springs which comprises: a reciprocating head having a well in the leading end thereof adapted to receive a valve spring retainer assembly; said head having a tapered increasing diameter recess diverging from the central portion of the well; a hollow plunger projecting into said tapered recess, and said tool being effective to advance the retainer cap assembly onto the valve stem while depressing the valve spring to cause the valve stem to move the lock out of the retainer into the recess while the plunger arrests movement of the lock relative to the stem to accommodate continued movement of the stem into the lock until the stem grooves are aligned with or axially beyond the beads of the lock and upon retraction of the tool the valve spring will move the cap into wedging engagement with the lock while the valve stem is retained in the lock.

8. The method of automatically assembling and locking a valve spring retainer cap and lock assembly onto a grooved valve stem which comprises: mounting a plastic tube between a pair of segmented valve stem locks with a head of the tube engaging the large end of the lock; inserting the locks into the tapered collar of a valve cap; deforming the free end of the tube over the small end of the collar to provide a pre-assembly of valve spring retainer cap and valve stem locks; pressing said assembly against the end of a valve stem surrounded by a valve spring to force the end of the valve stem into the deformed end of the tube while shifting the tube and valve stem locks through the large end of the collar; arresting the shifting of the locks relative to the'collar while continuing the shifting of the stem into the locks to eject the tube from the locks and to spread the locks apart for receiving the valve stem in locking relation therewith, and retracting the valve stem with the locks therearound into wedged engagement with the tapered collar of the retainer cap.

9. The method of pre-assembling a valve spring retainer cap-lock assembly which comprises the steps of: providing a valve spring retainer cap with a central tapered well; inserting a collet lock into said well; inserting a retaining member having an outturned lip at one end thereof into said well interiorly of the collet lock 7 with the lip overlying portions of one end of the collet lock and the other end of the retaining member projecting beyond the cap, and deforming the said other 4 end to flare it radially outwardly to a diameter greater than the minimum diameter of the tapered well.

10. The method of claim 9 wherein the said other end is deformed, thermally.

l 1. The method of claim 9 wherein the said other end is deformed sonically.

12. A tool for assembling a tapered outer diameter collet lock onto a grooved valve tip within the tapered well of a valve spring retainer cap which comprises: a housing; said housing having an end wall; an opening in said end wall; said opening communicating with a tapered diverging wall cavity in said housing; a plunger in said housing; said plunger having an open tubular end projectable into said cavity; said end axially movable in said housing; means for urging said end into said cavity; said open tubular end having an inner diameter greater than the outer diameter of a valve tip and less than the maximum outer diameter of a tapered collet lock when said lock is in its operative condition.

13. The tool of claim 12 wherein additional means are provided for limiting the movement of said end away from said cavity.

14. A tool for assembling a tapered outer diameter collet lock onto a grooved valve tip within the well of a valve spring retainer cap which comprises: a housing; said housing having a recess in one end thereof; the bottom of said recess opening to a tapered diverging wall cavity in said housing; a plunger in said housing; said plunger having an open tubular end projectable into said cavity; said end axially movable in said housing; means urging said end into said cavity, and said open tubular end having an inner diameter greater than the outer diameter of a valve tip and less than the maximum outer diameter of a tapered collet lock when said lock is in its operative condition.

15. The tool of claim 14 wherein the said means includes a coil spring entrapped between abutment means operatively connected to the said plunger and an interior wall of the said housing.

16. The tool of claim 15 wherein the means operatively connected to the plunger includes a piston received in a cavity in the said housing, the said piston having a radial wall, the said plunger having a ledge on its outer diameter, the said radial wall adapted to mate with the said ledge whereby movement of the said piston will be transferred to movement of the said plunger, the said piston movable in the said cavity, and the said spring entrapped between a portion of the said piston and an interior wall of the said housing.

17. The tool of claim 16 wherein an abutment plate is provided in the said recess at the bottom thereof, the said abutment plate having an opening therethrough, the said opening having a diverging wall and the said diverging wall extending from the said diverging wall of the said cavity at the recess end of the said cavity inwardly to the tapered well of a valve spring retainer cap received in the recess and bottomed against the plate.

18. The tool of claim 14 wherein the plunger has an inturned lip at the said tubular end, the lip defining the said inner diameter, and the lip providing an internal ledge adjacent the said end.

19. A tool for assembling a tapered outer diameter collet lock onto a grooved valve tip within the tapered well of a valve spring retainer cap which comprises: a housing having an end wall with an opening therethrough communicating with a tapered diverging wall cavity in the said housing; a hollow plunger in said housing; said plunger having an open end projectable into said cavity; said plunger axially movable in said 17 housing; means urging said endinto said cavity; a pilot pin in said plunger axially movable therein; said pin having a portion projectable through the open end of the plunger to the exterior of the housing through the end wall opening thereof, and means urging the said portion of the said pin out of the housing.

20. The tool of claim 19 wherein means are provided to limit movement of the said pilot pin portion out of the said housing.

21. The tool of claim 20 wherein selectively actuatable means are provided for preventing movement of the plunger independent of movement of the pilot pin.

22. The tool of claim 21 wherein the selectively actuatable means includes a detent assembly attached to the said plunger and movable therewith, the said detent assembly including a locking means actuatable to couple the said detent assembly to the said pilot pin.

23. The tool of claim 22 wherein the locking means includes a slidable claw lock indexable with a groove in the said pilot pin.

24. A tool for assembling collet locks onto a grooved valve tip within the well of a valve spring retainer cap which comprises: a housing; said housing having a diverging wall opening therein open to one end of the housing; a plunger in said housing; said plunger having an open end portion projectable into the said cavity; a pilot pin in said plunger; the said plunger movable in the said housing; the said pilot pin movable in the said plunger; a detent assembly attached to the said plunger, and the said detent assembly actuatable to prevent movement of the said plunger independent of movement of the said pilot pin.

25. The method of assembling a tapered outer diameter collet lock and a grooved outer diameter valve stem within the tapered well of a valve spring retainer cap received on a valve spring by a tool with a hollow axially movable plunger having therein an axially movable pilot pin which comprises the steps of:

a. aligning the tool with the valve stem with the retainer cap on the spring, the spring around the stem, and the lock in the well, the well positioned axially beyond the stem tip;

b. inserting the end of the pilot pin through the well interior of the lock;

c. moving the tool towards the stem with the cap abutting a portion of the tool;

d. compressing the valve spring to allow relative movement between the valve stem and tool and e. allowing relative movement between the plunger and pilot pin and the tool;

f. moving the collet lock out of the cap into the interior of the tool in contact with an end of the plunger;

g. arresting relative movement between the plunger and tool while continuing relative movement between the pilot pin and the tool with the end of the pilot pin contacting the valve tip;

h. spreading the collet lock interior of the tool;

i. moving the valve tip interior of the spread collet lock within the tool;

j. aligning the grooved stem of the valve with cooperating portions of the lock;

k. preventing movement of the plunger independent of movement of the pilot pin;

l. reversing movement of the tool with an end of the pilot pin in contact with the valve;

m. moving the collet lock and valve stem in unison out of the tool into the tapered well;

n. constricting the collet lock around the valve tip in the well; and

o. withdrawing the tool and plunger and pilot pin from the assembled valve spring retainer cap lock stem combination.

26. The method of claim 25 wherein the collet lock and cap are pre-assembled together with a hollow tube received interior of the collet lock with an outturned end overlying portions of the lock at the top of a cap and a flared end overlying portions of the cap at the opposite end which includes the additional steps of:

a. inserting the end of the pilot pin through the tube;

b. stripping the tube from the cap while moving the collet lock to the interior of the tool;

0. stripping the tube from the collet lock after arresting movement of the plunger with respect to the tool; and

d. retaining the tube on the pilot pin when the tool is withdrawn. 

1. The method of automatically assembling and locking a valve spring retainer assembly onto a grooved valve stem surrounded by a valve closing spring, the assembly including a tapered well collar with a segmented internally beaded valve lock received therein, the lock having a valve spring engaging a flange which comprises: placing the lock in the tapered well collar, feeding the assembly with the small end of the collar forming the leading end onto the valve stem while depressing the valve spring with the flange, thrusting the end of the stem against the lock in the collar to shift the lock toward the large end of the collar, retarding the shifting of the lock while continuing the thrusting of the valve stem thereagainst to move the stem into the lock and spread the lock segments apart, arresting the spreading of the lock, moving the valve stem through the lock until the stem groove is aligned with or beyond the internal bead of the lock and reversing the feeding of the assembly to expand the depressed valve spring for moving the tapered collar into wedged engagement with the valve lock constricting the lock segments around the valve stem, thereby securing the assembly to the stem with the lock beads seated in the groove and the locks forming a wedge connection between the valve stem and the collar.
 2. The method of claim 1 wherein the retainer assembly includes a tube extending through the lock segment and anchored on the retainer and the valve stem is thrust against the tube and ejects the tube from between the lock segments when the shifting of the lock is arrested.
 3. The method of claim 2 wherein the tube has an enlarged mouth receiving the end of the valve stem and a head overlying the valve lock and the thrusting action of the valve stem contracts the large end of the tube to pass through the collar and valve lock.
 4. A tool for automatically assembling and locking a valve spring retainer assembly onto a grooved valve stem which comprises: a housing adapted to thrust against a valve spring retainer assembly resting on a valve spring surrounding the grooved stem of a valve and having a tapered collar with an internally beaded valve lock therein; said housing having a increasing dimension tapered recess adapted to receive the valve lock and a spring loaded plunger projecting into said recess; said plunger receiving the valve lock thereagainst when the assembly is thrust against the valve stem and the valve lock shifts out of the tapered collar into the tapered recess of the housing; said plunger being hollow and adapted to receive the valve stem therein to arrest the shifting of the lock relative to the stem for aligning the stem groove with the internal bead of the lock, and said housing being retractable to allow the valve spring to move the collar into wedging engagement with the valve lock on the stem.
 5. The tool of claim 4 wherein the housing has a well receiving the retainer assembly and a plate bottomed in said well overlying the collar and having a central opening with a beveled opening diverging to the small end of the tapered recess of the housing.
 6. The tool of claim 4 wherein the hollow plunger has an end wall for contacting said valve lock and said end wall has inturned lips.
 7. A tool for automatically assembling valve spring retainer caps onto valve stems surrounded by valve closing springs which comprises: a reciprocating head having a well in the leading end thereof adapted to receive a valve spring retainer assembly; said head having a tapered increasing diameter recess diverging from the central portion of the well; a hollow plunger projecting into said tapered recess, and said tool being effective to advance the retainer cap assembly onto the valve stem while depressing the valve spring to cause the valve stem to move the lock out of the retainer into the recess while the plunger arrests movement of the lock relative to the stem to accommodate continued movement of the stem into the lock until the stem grooves are aligned with or axially beyond the beads of the lock and upon retraction of the tool the valve spring will move the cap into wedging engagement with the lock while the valve stem is retained in the lock.
 8. The method of automatically assembling and locking a valve spring retainer cap and lock assembly onto a grooved valve stem which comprises: mounting a plastic tube between a pair of segmented valve stem locks with a head of the tube engaging the large end of the lock; inserting the locks into the tapered collar of a valve cap; deforming the free end of the tube over the small end of the collar to provide a pre-assembly of valve spring retainer cap and valve stem locks; pressing said assembly against the end of a valve stem surrounded by a valve spring to force the end of the valve stem into the deformed end of the tube while shifting the tube and valve stem locks through the large end of the collar; arresting the shifting of the locks relative to the collar while continuing the shifting of the stem into the locks to eject the tube from the locks and to spread the locks apart for receiving the valve stem in locking relation therewith, and retracting the valve stem with the locks therearound into wedged engagement with the tapered collar of the retainer cap.
 9. The method of pre-assembling a valve spring retainer cap-lock assembly which comprises the steps of: providing a valve spring retainer cap with a central tapered well; inserting a collet lock into said well; inserting a retaining member having an outturned lip at one end thereof into said well interiorly of the collet lock with the lip overlying portions of one end of the collet lock and the other end of the retaining member projecting beyond the cap, and deforming the said other end to flare it radially outwardly to a diameter greater than the minimum diameter of the tapered well.
 10. The method of claim 9 wherein the said other end is deformed thermally.
 11. The method of claim 9 wherein the said other end is deformed sonically.
 12. A tool for assembling a tapered outer diameter collet lock onto a grooved valve tip within the tapered well of a valve spring retainer cap which comprises: a housing; said housing having an end wall; an opening in said end wall; said opening communicating with a tapered diverging wall cavity in said housing; a plunger in said housing; said plunger having an open tubular end projectable into said cavity; said end axially movable in said housing; means for urging said end into said cavity; said open tubular end having an inner diameter greater than the outer diameter of a valve tip and less than the maximum outer diameter of a tapered collet lock when said lock is in its operative condition.
 13. The tool of claim 12 wherein additional means are provided for limiting the movement of said end away from said cavity.
 14. A tool for assembling a tapered outer diameter collet lock onto a grooved valve tip within the well of a valve spring retainer cap which comprises: a housing; said housing having a recess in one end thereof; the bottom of said recess opening to a tapered diverging wall cavity in said housing; a plunger in said housing; said plunger having an open tubular end projectable into said cavity; said end axially movable in said housing; means urging said end into said cavity, and said open tubular end having an inner diameter greater than the outer diameter of a valve tip and less than the maximum outer diameter of a tapered collet lock when said lock is in its operative condition.
 15. The tool of claim 14 wherein the said means includes a coil spring entrapped between abutment means operatively connected to the said plunger and an interior wall of the said housing.
 16. The tool of claim 15 wherein the means operatively connected to the plunger includes a piston received in a cavity in the said housing, the said piston having a radial wall, the said plunger having a ledge on its outer diameter, the said radial wall adapted to mate with the said ledge whereby movement of the said piston will be transferred to movement of the said plunger, the said piston movable in the said cavity, and the said spring entrapped between a portion of the said piston and an interior wall of the said housing.
 17. The tool of claim 16 wherein an abutment plate is provided in the said recess at the bottom thereof, the said abutment plate having an opening therethrough, the said opening having a diverging wall and the said diverging wall extending from the said diverging wall of the said cavity at the recess end of the said cavity inwardly to the tapered well of a valve spring retainer cap received in the recess and bottomed against the plate.
 18. The tool of claim 14 wherein the plunger has an inturned lip at the said tubular end, the lip defining the said inner diameter, and the lip providing an internal ledge adjacent the said end.
 19. A tool for assembling a tapered outer diameter collet locK onto a grooved valve tip within the tapered well of a valve spring retainer cap which comprises: a housing having an end wall with an opening therethrough communicating with a tapered diverging wall cavity in the said housing; a hollow plunger in said housing; said plunger having an open end projectable into said cavity; said plunger axially movable in said housing; means urging said end into said cavity; a pilot pin in said plunger axially movable therein; said pin having a portion projectable through the open end of the plunger to the exterior of the housing through the end wall opening thereof, and means urging the said portion of the said pin out of the housing.
 20. The tool of claim 19 wherein means are provided to limit movement of the said pilot pin portion out of the said housing.
 21. The tool of claim 20 wherein selectively actuatable means are provided for preventing movement of the plunger independent of movement of the pilot pin.
 22. The tool of claim 21 wherein the selectively actuatable means includes a detent assembly attached to the said plunger and movable therewith, the said detent assembly including a locking means actuatable to couple the said detent assembly to the said pilot pin.
 23. The tool of claim 22 wherein the locking means includes a slidable claw lock indexable with a groove in the said pilot pin.
 24. A tool for assembling collet locks onto a grooved valve tip within the well of a valve spring retainer cap which comprises: a housing; said housing having a diverging wall opening therein open to one end of the housing; a plunger in said housing; said plunger having an open end portion projectable into the said cavity; a pilot pin in said plunger; the said plunger movable in the said housing; the said pilot pin movable in the said plunger; a detent assembly attached to the said plunger, and the said detent assembly actuatable to prevent movement of the said plunger independent of movement of the said pilot pin.
 25. The method of assembling a tapered outer diameter collet lock and a grooved outer diameter valve stem within the tapered well of a valve spring retainer cap received on a valve spring by a tool with a hollow axially movable plunger having therein an axially movable pilot pin which comprises the steps of: a. aligning the tool with the valve stem with the retainer cap on the spring, the spring around the stem, and the lock in the well, the well positioned axially beyond the stem tip; b. inserting the end of the pilot pin through the well interior of the lock; c. moving the tool towards the stem with the cap abutting a portion of the tool; d. compressing the valve spring to allow relative movement between the valve stem and tool and cap; e. allowing relative movement between the plunger and pilot pin and the tool; f. moving the collet lock out of the cap into the interior of the tool in contact with an end of the plunger; g. arresting relative movement between the plunger and tool while continuing relative movement between the pilot pin and the tool with the end of the pilot pin contacting the valve tip; h. spreading the collet lock interior of the tool; i. moving the valve tip interior of the spread collet lock within the tool; j. aligning the grooved stem of the valve with cooperating portions of the lock; k. preventing movement of the plunger independent of movement of the pilot pin; l. reversing movement of the tool with an end of the pilot pin in contact with the valve; m. moving the collet lock and valve stem in unison out of the tool into the tapered well; n. constricting the collet lock around the valve tip in the well; and o. withdrawing the tool and plunger and pilot pin from the assembled valve spring retainer cap lock stem combination.
 26. The method of claim 25 wherein the collet lock and cap are pre-assembled together with a hollow tube received interior of the collet lock with an outturned end overlying portions of the lock at thE top of a cap and a flared end overlying portions of the cap at the opposite end which includes the additional steps of: a. inserting the end of the pilot pin through the tube; b. stripping the tube from the cap while moving the collet lock to the interior of the tool; c. stripping the tube from the collet lock after arresting movement of the plunger with respect to the tool; and d. retaining the tube on the pilot pin when the tool is withdrawn. 